I currently live in a neighborhood with an HOA. The monthly dues are $55 and the amenities include 24/7 fitness center, community pool, parks and playgrounds, 1 acre dog park and miles of walking trails throughout the surrounding natural areas (in this case, desert.) The family does use all of these amenities quite a bit.
I tend to think it's a net positive since the monthly costs for a gym membership (with pool) for a family of 4 around here is gonna run in excess of $200/month. And then you have to actually go there, while my neighborhood pool is in the park across the street and the fitness center about 4 blocks away. So from those standpoints it's a win. On the other hand, I could live elsewhere without the amenities and just use public parks and pools and set up a workout area in my house. That would be a lot cheaper in the long run.
I guess the answer is different for all of us. I like the HOA as far as it maintains certain standards (as long as they don't go insane, I've heard all the horror stories.) I guess I figure the rest of the amenities are just a bonus. And in the grand scheme of things, there are lots of other areas I need to work on that will provide a bigger positive impact, (like dumping cable....)